The proposed Mayo Clinic Alzheimer's Disease Research Center (ADRC) is designed to be a major patient evaluation, research, and education resource for the upper Midwest. Epidemiology studies utilizing the population data base at the Mayo Clinic have provided the first age- and sex-specific incidence rates in the United States for dementing illnesses. The Mayo Clinic ADRC will extend these epidemiologic studies through a prospective community survey to establish prevalence rates in the urban and rural populations of Olmsted County, Minnesota. Case/control studies have been designed to evaluate etiologic risk factors including familial aggregation, environmental, and occupational toxic exposures. In the course of the community survey, a large number of non-demented elderly subjects will be identified, and normative values for commonly used neuropsychological tests for the elderly and the very elderly (80 and over) will be established. A unique feature of this ADRC is its ability to compare a community based population with a referral population with respect to demographic and clinical characteristics as well as survivorship. A neuropharmacology research project will study muscarinic acetylcholine receptor subtypes in Alzheimer's disease. A neuroimaging project will correlate volumetric changes in medial temporal lobe structures as measured by magnetic resonance imaging and functional changes as measured by single photon emission computed tomography with neuropsychological, clinical, and demographic characteristics of Alzheimer's disease patients and normal controls in a longitudinal fashion. The primary focus of the proposed ADRC in the initial years will be to establish a regional referral center for patients with Alzheimer's disease. The Mayo clinic is expanding its commitment to alzheimer's disease research by establishing an Alzheimer's disease research facility as part of its Jacksonville, Florida, clinic. It is anticipated that the proposed ADRC will expand to encompass the Jacksonville activities in future years.